How is the amount of fat removed in liposuction calculated?

This number is the amount of material that is removed from the body includling fluid and fat.  Best, Dr. Emer.

Thank you for the question. When a surgeon describes how much fat/fluid was removed they describe it as "lipoaspirate." 5 liters of lipoaspirate refers to the total volume of fat, and pre-injected fluid (tumescent fluid), that is removed. Typically, 30-50% of the total lipoaspirate volume is actually fat. 

Good question! While techniques vary somewhat, plastic surgeons usually inject approximately the same amount of fluid per area to be treated as they expect to remove as fat. For example if the surgeon estimates that one liter of fat needs to be suctioned from the belly, then one liter of fluid will be injected. After allowing the injected fluid and the medications in it to work for several minutes, then the combination of fat and injected fluid is sucked out, and that is called aspirate, as it is a combination of fat and injected material, and that is what is measured. Not all of the injected fluid is sucked out, as some of it is absorbed by the body. Usually, the estimated amount of fat is sucked out, in this example one liter, plus some fluid. 

I usually measure total volume, part of which is fat and part of
which is fluid.While some surgeons may
try to measure these separately, I find it difficult to come up with two
precise measurements.I would recommend
that you ask your surgeon what method he or she prefers, and how he or she
makes their measurements for a more specific answer.

During liposuction, tumescent fluid - sterile saline mixed with medications to control bleeding and pain - is injected into the treatment area and allowed to sit for a time.  This tumescent fluid is critical for successful liposuction. It loosens the fat and reduces complications.  Tumescent fluid is then removed along with the fat.  I count the total volume of fluid and tissue removed and never exceed 5 liters in one procedure.  The liposuction aspirate contains fat, tumescent fluid and blood.  Many patients just want to count the amount of pure fat removed, but unfortunately this is impossible to do.  First, there are microscopic amounts of fat mixed in with the fluid.  Also, the risks of liposuction increase when more than 5 liters of aspirate is removed - even though that aspirate contains more than just fat.

Determining how much fat that will be removed is done as an estimate.Some plastic surgeons will predetermine a certain amount to take out from a certain area and stop at that point.This is in my opinion an old-school way of doing liposuction.I simply stop removing fat when the results are what they should be.I do not predetermine how much fat is going to be removed during the procedure.I often predict based on experience.This is especially important when it comes to fat transfer since the volume of fat harvested will be used to treat another area.The amount of fat that can be removed through liposuction can be deceptive.I have had small people that I have taken highboy I'm so fat out.On the other and, I've had overweight people wear it seems difficult to get even at a few liters out.Loose skin can look deceptively like subcutaneous fat.This is one of the main reasons it can be difficult to pre-determine how much fat can be removed.The total aspirate or fluid that's removed during liposuction contains mostly fat and some of the numbing solution(tumescent solution)The percentage of fat varies from 60 to 90%.Best,Mats Hagstrom M.D.

Dear Ms. ClassicCurves,Thank you for your information and questions. Most Plastic Surgeons inject tumescent fluid which contains a combination:1) normal saline (wetting solution2) local anesthestic (lidocaine)3) epinephrine (decrease bleeding)this is measured in cc's and is recorded by area injected liposuctionis measured in cc by liposuction output referred to as: lipoaspirateexample: tumscent injected: 1,000 cclipoaspirate          : 1,000 cc (contains fat, tumescent fluid, blood and debris) fat compotent varies but can be 50-70%some tumescent fluid remains and is absorbed.If you are considering liposuction and I recommend that you make several consultative appointments with Plastic Surgeons who are experienced and Certified by the American Board of Plastic Surgery. In addition ideally they are members of the American Society for Aesthetic Plastic Surgery (denoting by membership as having met additional criteria and a focus on Cosmetic Plastic Surgery).I wish you my best and success,R. A. Hardesty, MD, FACSDiplomate and Certified by the Am. Bd. of Plastic Surgerywwwimagineplasticsurgery.com4646 Brockton AveRiverside, Ca 92506(951) 686-7600